1. What is a Solar Panel kWh Calculator?

Definition: This calculator estimates the energy output of solar panels in kilowatt-hours (kWh) based on panel wattage, operating hours, and a derate factor.

Purpose: It helps solar energy system designers and homeowners estimate potential energy production from solar panels.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( kWh \) — Energy output (kilowatt-hours)
• \( Wattage \) — Panel power rating (watts)
• \( Hours \) — Daily operating hours (hours)
• \( Derate \) — System efficiency factor (dimensionless)

Explanation: The formula converts watts to kilowatts (dividing by 1000) and accounts for system losses through the derate factor.

3. Importance of Solar Energy Calculation

Details: Accurate energy production estimates are crucial for system sizing, financial analysis, and energy savings projections.

4. Using the Calculator

Tips: Enter panel wattage in watts, daily operating hours, and derate factor (default 0.8). All values must be > 0.

5. Frequently Asked Questions (FAQ)

Q1: What is a typical derate factor?
A: Most systems use 0.8 (80% efficiency) accounting for temperature, wiring, inverter, and other losses.

Q2: How do I estimate daily operating hours?
A: Use "peak sun hours" for your location (typically 3-6 hours depending on geography and season).

Q3: Should I use panel nameplate rating or actual output?
A: Start with nameplate rating, but consider real-world conditions may reduce actual output.

Q4: How do I calculate monthly or annual production?
A: Multiply daily kWh by number of days in period, adjusting for seasonal variations.

Q5: Does this include battery storage losses?
A: No, this calculates panel output only. Additional derating may be needed for battery systems.